Log::Log4perl::Appender::RRDs appenders facilitate writing data
to RRDtool round-robin archives via Log4perl. For documentation
on RRD and its Perl interface RRDs (which comes with the distribution),
check out http://rrdtool.org.
Messages sent to Log4perl's RRDs appender are expected to be numerical values
(ints or floats), which then are used to run a rrdtool update command
on an existing round-robin database. The name of this database needs to
be set in the appender's dbname configuration parameter.
If there's more parameters you wish to pass to the update method,
use the rrdupd_params configuration parameter:
log4perl.appender.RRDapp.rrdupd_params = --template=in:out
To read out the round robin database later on, use rrdtool fetch
or rrdtool graph for graphic displays.